JP2002529843A - Image CNC program for generating machine parts - Google Patents

Abstract

(57) Abstract: The present invention relates to a system (44) for machining a part (12) having flat and curved surfaces (18, 20) and rotating surfaces (12, 14, 16), and a CNC program. (78, 80) comprising an interface for inputting information of the portion (12) including for at least one surface (48) corresponding to at least one surface of the portion (12); , Direction and surface (48) comprising the type of machining function corresponding to the surface (48). A set of features corresponding to each surface (48) is also input via the interface (32). Thereafter, a set of machining operations for machining the set of features is generated. The processing operation is optimized (38) so that a minimum step (74) time for processing the part (12) is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a system and method for automatically generating a computer numerical control (CNC) machining program for machining a portion having various flat surfaces and / or curved surfaces. More specifically, the present invention relates to a complex tooling intensive pa
rt) as a plurality of simple planes and curved surfaces and related elementary features (e.g., holes, slots, and pockets) in those surfaces to generate a CNC program.

BACKGROUND OF THE INVENTION CNC machines use a plurality of cutting tools in a series of machining steps to cut material from a workpiece to produce a specific portion. The CNC machine operates the tool and the workpiece in a three-dimensional space along a predetermined path, thereby facilitating the interaction between the two and the material removal. The examples of the CNC machine tool shown in FIGS. 1A, 1B, 2 and 3 are superior in accuracy and productivity as compared with a manual machine.

A computer executes a command group of a CNC program to execute a CNC.
Monitor the operation of the machine. These commands define the tool to be used, cutting feed and rotational speed information for the tool, and describe the tool path required for material removal for a given process. CNC machines recognize a special language that depends on the machine manufacturer. The language of CNC machines is generally unwieldy for humans and not user-friendly.

[0004] Manufacturing support (CAM) software systems may simplify the process of generating a CNC program. A CAM system allows for interactive and often 3D solid model format graphic entry. Traditional CAM
The systems originated from Computer Aided Design (CAD) and Computer Aided Technology (CAE) systems. The focus of CAD and CAE is on the functionality and properties of the whole part. In this context, solid modeling is essential for investigating various properties of a material, such as, for example, heat distribution and deformation under stress.

[0005] Unlike design and technology applications, machining applications are essentially surface treatments. Often, only a small portion of the entire surface of the part is machined. For example, only the fitting surface between the casting parts may be processed, and most of the surface may be left unprocessed. Mechanics are only interested in the multiple surfaces that must be machined and the relationships between those surfaces. While the global coordinates of all subelements are known in solid models created for design and technology applications, in machining operations, the operator requires a local coordinate system for each surface that needs to be machined. Must be created. This process is difficult and labor intensive for machine tool operators.

A typical mechanical part has one or more surfaces that can each include a number of standard mechanical features, such as holes, slots, pockets, grooves, screws, and the like.
The mechanical drawing of the part contains sufficient information about the geometry, features and part materials that define the part. Features are typically referenced to the surface on which they are located. Each surface is depicted as a separate view of the part. The surfaces can be planes or curved surfaces generated by milling, or curved or rotating surfaces generated by turning. Machining these features involves the use of multiple cutting tools and the setting of machining parameters for each step. For example, a simple tapped hole would require a minimum of four tools: a center drill, a drill, a tap, and a chamfer tool. Numerous parameters such as speed, feed rate and depth of cut may be required for each step. In order to optimize the manufacturing process, it may be necessary to change the processing sequence from the order in which the data was first entered.
For cost-effective manufacturing, it is necessary to reduce the time spent generating an effective CNC program and to improve the usefulness of tools and equipment.

[0007] The tools and process sequences for the CNC program in most CAM systems are usually operator defined as they depend on machine performance and operator skill (varies from factory to factory). Thus, traditional CAM systems provide tool path calculations for multiple jobs with well-defined free-form surfaces, while having many different features that require the use of multiple tools. Does not provide much assistance for processing.

One method for simplifying the input of tool information is described in US Pat. No. 4,521,860 to Kanematsu et al. This patent teaches a special C that allows entry of three modes of operation connected to dedicated keys on the front panel.
An NC computer is disclosed. Each mode includes a predetermined number of operation units, such as drilling, tapping, slot milling, and pocket milling. These units allow the input of a combination of reusable geometric and tool information. By establishing hard rules for inputting processing data to a given unit, the computer can reuse information within the boundaries of one surface of the part.

Further, as a CAM system for a planar (two-dimensional) milling machine, CNC
Some have CNC program automatic generators for tool intensive parts produced on drilling, boring or planar milling machines. These systems leverage the operator's expertise in machining features of a part on a plane and reapplying this knowledge to machining of the same or similar features on the same or different parts. It has the ability to capture. To further simplify the program preparation process, the system allows the operator to identify several planes on the part and program each side independently to generate one CNC program for the entire part. Make it possible.

[0010] The CNC milling machine and machine center illustrated in FIG. 1A is used to create essentially flat or uneven surfaces and machine features (holes, slots and pockets, etc.) on these surfaces. In this system, the workpiece moves linearly,
The cutting tool simply rotates. The part moves relative to the cutting tool in the X, Y, and Z directions. The multi-axis machining center illustrated in FIG. 1b has an X-axis, a Y-axis, and a Z-axis.
It is allowed to incline at A, B and C angles about the axis, respectively. Simpler machines cut material only on one axis, such as CNC drilling and boring machines.

A CNC lathe (CNC turning machine) illustrated in FIG. 2 includes a portion having a curved surface inside and outside, such as a solid or hollow cylinder, a cone, a hemisphere, and a groove and a screw generated by the rotating motion of the portion. And producing a portion having a plurality of surface features including: In order to create a round surface, the CNC lathe rotates the work and moves the cutting tool along the plane of the rotation axis. In this respect, CNC lathes differ substantially from CNC milling, drilling and boring machines. The tool of CNC lathe is usually
It has only one cutting surface. Thereby, further restrictions are added to the tool directionality in the CNC program automatic generation process.

The latest CNC turning / milling machining center illustrated in FIG.
It combines the capabilities of a C milling machine, drilling machine, boring machine and lathe. Complex parts with flat and curved surfaces can be manufactured completely in one setup with one machine. The turning / milling machine creates parts with greater accuracy than other CNC machines because it eliminates the need to reposition the workpiece between turning and milling. However, the programming of such powerful machines poses a significant challenge for machine operators.

SUMMARY OF THE INVENTION The present invention provides a visual system and method for automatically generating a CNC program for a machined part having flat and curved surfaces. These parts generally require multiple faces to visually define the parts. A surface is a two-dimensional view of a portion representing a graphical representation of information describing a particular surface and many features (eg, openings, slots, grooves, screws, etc.) that are dimensionally related to the particular surface. The surface may indicate a flat surface or a curved surface. Portions where a great deal of tools are required to machine a feature are generally described as "tool intensive portions".
The present invention provides a graphical user interface in which multiple windows are displayed on a computer monitor and accessed simultaneously.
es) Use (GUI).

The system of the present invention comprises: (a) a plurality of surfaces, each surface corresponding to a surface of the portion, displayed in a separate window; and (b) a set of features associated with each of the plurality of surfaces. , (C) a graphical interface for inputting part information for defining a set of machining steps and cutting tools associated with each element of the set of features. The system of the present invention also includes a data store memory element holding a data store for storing part information in communication with the interface, a process optimization module for receiving part information in communication with the data store memory element. Is provided. The process optimization module is a set of machining processes and cutting tools,
And a memory element for maintaining a material machinability database of selected process parameters for selective instruction of a set of machining steps thereafter. The code generation module receives the ordered set of machining steps in communication with the process optimization module. The code generation module comprises a shape subsystem for using the shape file to create the shape file and then convert the ordered set of machining steps into a CNC program for partial machining. .

The method of the present invention comprises: (1) a plurality of surfaces, each surface corresponding to a surface of the portion; (2) a set of features associated with each of the plurality of surfaces; and (3) each of the set of features. Entering part information defining a set of machining steps and cutting tools associated with the element; storing the part information in a data store memory element; and a set of machining steps using a material machinability database. And converting the ordered set of mechanical steps into a CNC program for partial machining.

DETAILED DESCRIPTION OF THE INVENTION An apparatus and method for generating a CNC program for a machined part having planar, curved and rotating surfaces according to the present invention is illustrated. FIG. 4 shows an engineering drawing 10 of a part 12 having a plurality of planes, curved surfaces and rotating surfaces. Part 1
All the information needed to define 2 can be obtained from FIG. Drawing 1
0 includes information on the dimensions of the picture defining the rotation planes 12, 14, 16 and the planes 18, 20. The portion 12, detailed in FIG. 10, is typically machined from a cylindrical column 76 mm (3 inches) long and 12.7 mm (0.5 inches) in diameter. Drawing 10
Is a printed paper drawing or Drawing Exchange Format
(DXF) or an electronic drawing file in a standard format such as the Initial Graphics Exchange System (IGES). Drawing 10 includes the geometry of portion 12 and the material properties of the workpiece used to fabricate portion 12. If the drawing 10 is a paper drawing, the information can be entered into the system of the present invention using a conventional CAD program embedded in the system of the present invention. This CAD program
As shown in FIG. 10, a graphic tool is provided for the operator to enter part information into the system.

The present invention may be implemented using hardware, software, or any combination thereof. Further, the system of the present invention may be incorporated into any one of the devices illustrated in FIGS. FIG. 5 shows an example of the components of the system of the present invention. These include a central processing unit (CPU) 24, a control program memory element 26, a cycle database memory element 28, a tool database memory element 30, an interface module 32, and an operation module 34. CPU 24 may be any processor capable of controlling the operation of the present invention and controlling such a system. The control program memory element 26 stores a control program, which causes the CPU 24 to operate the system and execute the method of the present invention. The control program memory element 26 is
Or a separate memory element. Similarly, cycle database memory element 28, tool database memory element 30, and interface module 32 may be incorporated into CPU 24, may be separate elements, or may be optional to enhance the functionality of the present invention. May be combined. The operation module 34 includes a data store memory element 36, a process optimization module 38, and a code generation module 40.

The interface module 32 allows the operator of the present invention to open a GUI, for example, a window 42 similar to that shown in FIG. Window 42 includes a menu pull-down system 44 and an icon system 46, and operates in a conventional manner. The operator uses the menu pull-down system 44 and / or the icon system 46 to enter part information describing each surface (14-20) of the portion 12. The part information is stored in the data store memory element 36, and the data store memory element 36 is a memory element capable of storing data. The part information includes a plurality of surfaces 48, different surfaces of the portion 12 (14 to 2).
0) is included. Each of the faces 48 needed to define all the surfaces of the portion 12 is shown in a separate window and stored in connection with the data store memory element 36. For example, face 48a is window 42a
The face 48b is shown in the window 42b, and the face 48c is shown in the window 4b.
2c. The surface information includes the boundaries, orientations, and types of machining functions required to machine the individual surfaces 48. If the drawing 10 is an electronic file, the geometry of each surface 48 is preferably illustrated in a separate surface window 42. However, if this method is not followed, the CAD tool allows the geometry of each face 48 to be copied and pasted into a separate face window 42.

Since the faces can be of different topological types, a graphic icon 50 at the corner of a given face window 42 graphically identifies the type of face. For example, the icon 50a displayed in the window 42a indicates a turn surface, the icon 50b displayed in the window 42b indicates a surface cut on the flat end face of a round work, and the icon displayed in the window 42c. 50c shows a cylindrical cutting surface. The capabilities of the individual CNC machines determine the choice of available surfaces. Using the pull-down menu system 44 available in the face windows 42, a dialog window 52 associated with each face window 42 may be opened. The surface parameter dialog window 52, an example of which is shown in FIG. 7, includes a pictorial representation 54 of each surface type corresponding to the icon 50, and a plurality of descriptive parameters of the surface boundary and a surface of the CNC machine adjustment system. And parameters related to positioning. Using the surface parameter dialog window 52, the operator may enter values for each of the boundary and positioning parameters to define an individual surface. The information for each side entered using the dialog window 52 is stored separately in the data store 36 in the form of a record for each side 48.

For each face 48, information defining a set of features associated with that face,
It is entered into the system using a GUI. Using the pull-down menu system 44, the operator can open a cycle dialog window 56, an example of which is shown in FIG. The cycle dialog window 56 allows the operator to define a cycle for machining a particular feature. A cycle is a series of steps for machining a particular feature. For example, the cycle illustrated in FIG. 8 includes four steps to create a chamfered and tapped hole. Cycle parameter information includes tooling, cutting paths, and other process information needed to machine a particular feature. Cycles include process type, canned cycle, hole diameter,
Includes hole depth and tool ID number. Using the cycle dialog window 56, the operator may create a new cycle or access a cycle database stored in the cycle database memory element 30 to retrieve a predefined cycle. Each time a new cycle is defined, it is stored in the cycle database for later use. The retrieved cycle can be reused or modified to create a new cycle. The cycle dialog window 56 displays cycle parameter information using an easily modifiable table 60 having icons 62 of the tools used in the cycle.
This facilitates a quick and easy change of an existing cycle to create a new cycle. Once a cycle is defined, it is applied to the surface 48, through which a specific cycle dialog window 56 is opened and features of the surface (eg,
A graphical representation of holes, slots, pockets, grooves and threads) is shown in workspace 58 of face window 42 using a graphical representation. The cycle for machining each feature on an individual surface must be applied to that surface. A list of all cycles for the individual faces appears in workspace 58. Each feature requires a cycle to machine the feature. A cycle record containing cycle parameter information is created for each new feature, and the cycle record is stored in the data store and associated with the appropriate surface information.

When defining a new cycle or modifying an existing cycle, the system retrieves information from the tool database stored in the tool database element 30. The tool database stores a tool record for each tool available to the CNC machine. The tool database provides the CNC machine with a complete, predefined specification of tool capabilities. Using the pull-down menu system 44,
The operator can open a tool dialog window 64. The tool dialog window 64 displays a number of tools available to the operator for use with the CNC machine, such as end mills, face mills, slot mills, centering tools,
Groove milling tool, thread milling tool, spot drill, drill, cornering tool, bore (bores), reams (reams), taps, chamfers,
It allows to define facing turning tools, slotting tools, turning cutters, thread cutting tools, etc. The tool dialog window 64 includes a pictorial representation 66 of a particular tool and a list of tool parameters. Once the tool parameters describing the tool have been entered, they are permanently stored in the tool database as long as the tool is available on a given CNC machine. The system is capable of simulating and displaying tool paths and processes, material removal to form a particular part of a feature. The system can define special custom-shaped tools given a given CNC program.

Once all features have been described for all surfaces, the surface information and machining steps in each cycle are transmitted from the data store 36 to the memory 68 of the process optimization module 38. The process optimization module 38 schedules the processing steps so as to minimize the process time. In the process optimization module 38, the cycles are treated as simple independent machining steps, and these machining steps are grouped for each tool so that the number of tool changes is minimized. Further, the process order is also determined by the restrictions of the CNC machine. For example, in the drilling process, small diameter drills are used before large diameter drills, and taps are used after using these drills. In milling, a roughing mill is used before the finishing mill.

The process optimization module 38 uses the material workability database stored in the material database memory element 70 to select the optimal tool cutting speed and feed rate for each process. The database of material workability includes recommended rates of material transfer as a function of tool parameters such as cutting edge diameter and number. The workability database information is represented by a customizable graph 72 as shown in FIG. 10, for example. The operator can modify the standard graph by dragging points up and down on the graph to suit his experience. Once selected, the cutting speed and feed rate are automatically reused in later applications where the material is the same and the tool is different. Additionally, the process optimization module minimizes process time by eliminating excessive tool changes and excessive part repositioning to machine different surfaces.

The process optimization module 38 generates a process table 74 as illustrated in FIG. The process chart 74 has the processing steps selectively ordered. The columns of the process table 74 correspond to the machining processes, and display tools and processes. Each column includes a tool icon, a feed rate, a tool speed, a surface on which a process is performed, and a time required for the process. The special synchronization input allows the operator to schedule the process to prevent collision of tools on a machine with multiple tool holding turrets and multiple spindles processing simultaneously. The latter allows the material to be cut simultaneously from both ends of the part. Rearranging the displayed columns of the process chart 74 changes the process order of the apparatus.

The code generation module 40 uses the data of the process chart 74 and the specific shape file of the device. This shape file is stored in a shape file memory element 76 to generate a set of codes 78 for use in a CNC device as illustrated in FIG. A device specific shape file is created using the post shape subsystem 80. This allows a user with advanced knowledge to customize the output of the code generation module 40 to generate a code in a format suitable for any type of CNC device. In a manufacturing process, if a part must be manufactured with one or more CNC devices or a combined spindle device capable of performing one or more CNC processes, the code generation module 40 may use a plurality of CN devices.
A C program must be generated. These programs may have special code to synchronize the execution of similar steps.

The shape file created by the post shape subsystem 80 is used by the code generation module 40 as a set of templates for converting process chart data into CNC program code 78. Individual templates correspond to different actions, such as G01 = linear movement and G06 = tool change. In the template, for example, X, Y, Z, <X-COORD>, <Y-COOR
A combination of specific symbols (referred to as letter address symbols) such as variables such as D> and <Z-COORD> is used. For example, a template for linear movement is generally “G01X <X-COORD> Y <Y-COORD> Z <Z-COORD>”
Is shown as The code generation module 40 converts the template into the CNC program code 78 by using the corresponding values from the process chart 74 instead of the variables. For example, when the tool moves to points X = 1, Y = 2, Z = 3, the template for the linear movement is converted to a character string “G01X1.0Y2.0Z3.0”. The resulting CNC program code 78 is a text file recognizable by the CNC control program.

The post-shape subsystem 80 uses a GUI “point and click” approach to creating templates from the variables displayed on the screen in windows. In addition to the template, the post shape subsystem 80 allows the user to:
Allows customization of code for all devices, such as, but not limited to, type of operation, refrigerant control, and tool wear. The post shape subsystem 80 has a description of all devices.

When machining curved surfaces and planes on a CNC rotary mill with multiple spindles and multiple tool holding turrets and multiple cartridges, the post-shaped subsystem 80 has two “forks”. One fork has the full description of the CNC mill and one fork has the full description of the CNC lathe. In a manufacturing process, if a part must be manufactured on one or more CNC devices or on a compound spindle device capable of performing one or more CNC processes, the code generation module 40 creates a plurality of CNC programs.

To validate the last CNC program, any code verifier can read, translate, and execute each line of CNC code and display the resulting action. The 3D solid model simulator reproduces the movement of the cutting blade, the removal of material, and the turning of the workpiece into the shape of the workpiece. The system visually simulates the configuration of a particular feature by displaying a demonstration of the path of the tool in conjunction with the operation of the device to the particular feature. In addition, the system visually simulates the configuration of all features on the surface by displaying a demonstration of all tool paths for all tools in conjunction with operation of the device for the surface.

Implementing the present invention involves defining a part by organizing data into traditional features, ie, faces, holes, slots and threads, and
Uses data entered into the AM system. To machine each feature, multiple tools and multiple steps are assigned in each cycle. New information for a particular feature entered into the system is automatically stored in the cycle and tool databases and can be reused when programming other parts with similar features. This approach eliminates repetitive data entry and data storage, as compared to conventional CAM systems that require the orderly entry of tool and process information, and the process is a CNC for each new part.
To be performed by the device.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes of the invention, and thus are deemed to be indicative of the scope of the invention rather than the foregoing detailed description of the invention. Refer to the range.

[Brief description of the drawings]

FIG. 1 (FIGS. 1a and 1b) illustrates an example of a multi-axis CNC milling machine.

FIG. 2 illustrates an example of a CNC lathe having two tool turrets.

FIG. 3 illustrates an example of a CNC rotary mill center.

FIG. 4 shows an engineering drawing of a machinable part.

FIG. 5 shows a block diagram of an embodiment of the system of the present invention.

FIG. 6 illustrates three examples of GUI windows for use in the present invention.

FIG. 7 illustrates three examples of alternative windows of a GUI for use with the present invention.

FIG. 8 illustrates another example of a GUI window for use in the present invention.

FIG. 9 illustrates three examples of alternative windows of a GUI for use with the present invention.

FIG. 10 illustrates another example of a GUI window for use in the present invention.

FIG. 11 illustrates an example of another window of a GUI for use with the present invention.

FIG. 12 illustrates an example of a program code generated according to the present invention.

FIG. 13 illustrates a three-dimensional solid model made according to the present invention.

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Claims (12)

[Claims] 1. A CNC machine for machining a portion having a flat surface, a curved surface and a rotating surface.
A system for generating a program, comprising: (a) a plurality of surfaces corresponding to the plurality of surfaces of the portion and displayed in a separate window; (b) a set of features associated with each of the plurality of surfaces; A) a graphical interface for entering part information for defining a set of machining steps and cutting tools associated with each element of the set of features; and a graphical interface connected to the graphical interface for storing the part information. A data store memory element for securing a data store; and a memory element for holding a material workability database for selecting the set of machining steps and machining parameters for the cutting tool; A process optimization module connected to an element for receiving the part information; Connected to the optimization module, the code generation module receives the requested machining process, creates a shape file, and then converts the requested machining process into a CNC program for machining the part using the shape file A code generation module that includes a shape subsystem that performs the configuration. And a memory element for securing a cycle database for storing a plurality of cycle records in which each record holds information defining a machining process and a cutting tool for machining one feature. Claim 1
System. 3. The apparatus of claim 1, further comprising a memory element for securing a tool database storing a plurality of tool records, each record holding information defining a tool available in the system. system. 4. The system of claim 1, wherein the information defining the surface includes a boundary, a direction, and a type of machining function. 5. The system according to claim 1, wherein the CNC program is a CNC program for any one of a rotary mill, a multi-axis CNC machining center, and a multi-axis lathe. 6. A CN for processing a portion having a flat surface, a curved surface, and a rotating surface.
A method of generating a C program comprising: (a) a plurality of surfaces corresponding to a plurality of surfaces of the portion and displayed in a separate window; (b) a set of features associated with each of the plurality of surfaces; c) inputting part information for defining a set of machining steps and cutting tools associated with each element of the set of features; storing the part information in a data store memory element; Selectively requesting a set of machining steps using a gender database; and converting the requested set of machining steps into a CNC program for machining the portion. 7. The method of claim 6, wherein the information defining the surface includes a boundary, a direction, and a type of machining function. 8. The step of inputting the set of machining steps includes creating a cycle record in a cycle database, wherein each of the cycle records comprises one.
7. The system according to claim 6, wherein information is defined that defines a machining step and a cutting tool for machining one feature. 9. The method of claim 6, wherein selectively requesting a set of machining steps includes selecting an optimal tool cutting speed and feed rate for each element of the set of machining steps. The described method. 10. The method of claim 6, wherein converting the requested set of machining operations to a CNC program includes customizing a shape subsystem to create a machine specific shape file. 11. The system according to claim 6, wherein the CNC program is a CNC program for any one of a turning / milling machining center, a multi-axis CNC machining center, and a multi-axis lathe. 12. A C for processing a portion having a flat surface, a curved surface, and a rotating surface.
In the method for generating an NC program, part information defining a surface corresponding to one surface of the portion, the boundary information including a boundary, a direction, and a type of a processing function required for processing the surface is generated. Generating a set of part features corresponding to the surface of the part, and a part information defining a set of machining steps and a cutting tool corresponding to the set of part features; Generating a process table including an optimized and required list of cutting tools and a cutting tool, and generating a CNC program before processing the part based on the process table. Method.